Model Code Decoding

• D638: Base series, NG06 (ISO 4401-03) pressure/flow (p/Q) control servo valveMoog Inc..

• 206:

  • 2: Rated flow 20 L/min (Δp=35 bar/land).

  • 0: Max pressure 350 bar (P/A/B ports)Moog Inc..

  • 6: 4-way spool, linear, zero overlap, spring-centered, p/Q control (pressure + flow limiting)Moog Inc..

• 0001: Standard analog interface (±10 V), no fieldbus, firmware revision 1Moog Inc..

Technical Specifications

• Part Number: D638-206-0001

• Valve Size: NG06 (ISO 4401-03, Cetop 3)Moog Inc..

• Control Function: 4-way p/Q (pressure + flow) control, spring-centered (fail-safe: P→A, B→T on power loss)Moog Inc..

• Rated Flow (Δp=35 bar/land): 20 L/min (±10%).

• Max Flow: 40 L/min.

• Operating Pressure:

  • P/A/B ports: 350 barMoog Inc..

  • T port: 50 bar (std) / 350 bar (Y-port option)Moog Inc..

• Step Response (0→100%): ≤12 ms (210 bar)穆格中国.

• Hysteresis: <0.2% (pressure control)Moog Inc..

• Linearity: <0.5%Moog Inc..

• Electrical:

  • Supply: 24 VDC (18–32 VDC), 1.2 A maxMoog Inc..

  • Command: ±10 V (std); ±10 mA / 4–20 mA optionalMoog Inc..

  • Feedback: LVDT (spool position, internal) + integrated A-port pressure transducerMoog Inc..

  • Protection: IP65 (mated connector)Moog Inc..

• Fluid: Mineral oil (DIN 51524), viscosity 5–400 mm²/s.

• Temperature:

  • Ambient: −20°C to +60°C.

  • Fluid: −20°C to +80°C.

• Mass: ~2.7 kg.

• Seals: FPM (Viton, high-pressure std) / NBR (option).

Interface & Communication Configuration

• Electrical Interface: Analog ±10 V command + 24 VDC; no fieldbus (0001)Moog Inc..

• Feedback: Integrated LVDT (spool position) + A-port pressure sensor (closed-loop p/Q control)Moog Inc..

• Mounting: 4-hole NG06 (ISO 4401-03), M5 bolts, 8–10 Nm.

• Porting: P, A, B, T; Y-port available (high backpressure)Moog Inc..

Core Functions

1. 350 Bar High Pressure: For high-pressure industrial hydraulic systemsMoog Inc..

2. 20 L/min Precise p/Q: Balanced flow + closed-loop pressure regulation for medium actuatorsMoog Inc..

3. Direct-Drive Design: No pilot oil, pressure-independent dynamicsMoog Inc..

4. Integrated Digital Electronics: Onboard p/Q controller, no external PLC requiredMoog Inc..

5. Fast Response: ≤12 ms step response, low hysteresis/non-linearity穆格中国.

6. Fail-Safe Spring Center: Safe position on power lossMoog Inc..

Application Scenarios

• High-Pressure Force/Pressure Control: Hydraulic presses, clamping systemsMoog Inc..

• Test Benches: Fatigue, vibration, and component durability testing (force-controlled)Moog Inc..

• Machine Tools: High-speed, accurate hydraulic actuators with pressure limitingMoog Inc..

• Plastics Machinery: Injection molding (clamp force control)Moog Inc..

• General Hydraulics: High-pressure, dynamic pressure + flow control systemsMoog Inc..

Compatibility & Differences

• Base Model: D638-206-0001 = analog 20 L/min/350 bar 4-way p/Q valveMoog Inc..

• vs D636-313-0001: D636 = flow-only; D638 = p/Q (pressure + flow) controlMoog Inc..

• vs D639-206-0001: D639 = NG10 (Size 05), higher flow (40–100 L/min)Moog Inc..

• vs D638-406-0001: 406 = 40 L/min; 206 = 20 L/min (same pressure/p/Q function).